Relocate Matrix/Vector code to lib where plugins can use it

Also, tweak the perspective projection scaling to fill out the area
a bit more, and change the visualization editor to use the grid's
size when setting the path dimensions.

Also, note gimbal lock.

PluginCommon/Matrix44.cs

@@ -17,7 +17,7 @@ using System;
 using System.Collections.Generic;
 using System.Text;
 
-namespace CommonUtil {
+namespace PluginCommon {
     /// <summary>
     /// Simple 4x4 matrix.
     /// </summary>
@@ -26,7 +26,6 @@ namespace CommonUtil {
             get { return mVal; }
             private set { mVal = value; }
         }
-
         private double[,] mVal;
 
         public Matrix44() {
@@ -67,7 +66,7 @@ namespace CommonUtil {
             double sycx = sy * cx;
             double sysx = sy * sx;
 
-            bool useXyz = false;
+            bool useXyz = true;
             if (useXyz) {
                 // R = Rz * Ry * Rx (from wikipedia)
                 Val[0, 0] = cz * cy;

PluginCommon/Vector3.cs

@@ -15,7 +15,7 @@
  */
 using System;
 
-namespace CommonUtil {
+namespace PluginCommon {
     /// <summary>
     /// Simple 3-element column vector.
     /// </summary>
@@ -32,7 +32,6 @@ namespace CommonUtil {
             get { return mZ; }
             set { mZ = value; }
         }
-
         private double mX, mY, mZ;
 
         public Vector3(double x, double y, double z) {

PluginCommon/VisWireframe.cs

@@ -172,8 +172,9 @@ namespace PluginCommon {
                 }
             }
 
-            // TODO(maybe): confirm that every face has a vertex.  Not strictly necessary
-            // since you can do orthographic-projection BFC without it... but who does that?
+            // TODO(maybe): confirm that every face (i.e. normal) has a vertex we can use for
+            // BFC calculation.  Not strictly necessary since you can do orthographic-projection
+            // BFC without it... but who does that?
 
             msg = string.Empty;
             return true;

SourceGen/RuntimeData/Help/visualization.html

@@ -111,7 +111,10 @@ render with a perspective projection and without culling.</p>
 axes.  The viewer provides a conventional right-handed coordinate system,
 with +X toward the right, +Y toward the top of the screen, and +Z
 coming out of the screen.  Positive rotations cause a counter-clockwise
-rotation when looking down the axis in the positive direction.</p>
+rotation when looking down the axis in the positive direction.  The
+rotations are performed with a matrix using Euler angles, and are
+subject to gimbal lock (e.g. if you set Y to 90 degrees, X and Z rotate
+about the same axis).</p>
 <p>If you check the "Animated" box, you can add a simple spin.  Choose
 the number of degrees to rotate per frame, how many frames to generate before
 resetting, and the delay between each frame.  Clicking the "Auto" button

SourceGen/WireframeObject.cs

@@ -52,6 +52,10 @@ namespace SourceGen {
                 Vec = new Vector3(x, y, z);
                 Faces = new List<Face>();
             }
+
+            public override string ToString() {
+                return Vec.ToString() + " + " + Faces.Count + " faces";
+            }
         }
 
         private class Edge {
@@ -226,7 +230,7 @@ namespace SourceGen {
             double scale = 1.0 / mBigMag;
             if (doPersp) {
                 // objects closer to camera are bigger; reduce scale slightly
-                scale = (scale * zadj) / (zadj + 0.5);
+                scale = (scale * zadj) / (zadj + 0.3);
             }
 
             Matrix44 rotMat = new Matrix44();

SourceGen/WpfGui/EditVisualization.xaml.cs

@@ -605,7 +605,7 @@ namespace SourceGen.WpfGui {
                     previewGrid.Background = Brushes.Black;
                     previewImage.Source = Visualization.BLANK_IMAGE;
                     double dim = Math.Floor(
-                        Math.Min(previewImage.ActualWidth, previewImage.ActualHeight));
+                        Math.Min(previewGrid.ActualWidth, previewGrid.ActualHeight));
                     WireframeObject wireObj = WireframeObject.Create(visWire);
                     wireframePath.Data = Visualization.GenerateWireframePath(wireObj, dim, parms);
                     BitmapDimensions = "n/a";